At the present time, feeding powdered coffee to machines which make and fill filter-paper coffee pods is performed by a unit fitted to the machine itself where the unit consists of feeder devices designed to drop an amount of coffee into a dosing chamber.
The dosing chamber is horizontal and inside has a sliding, reciprocating piston designed to push the dose of coffee dropped down by the feeders into a vertical feed tube from where the coffee drops down into a series of circular filter paper impressions; the impressions are formed by embossing a strip of filter paper on a corresponding series of circular recesses on an intermittent conveyor which forms the pod shaping and conveying line of the packing machine.
Vertical, reciprocating pressers are mounted at the feed tube and compress the coffee in the circular impressions before the impressions are covered on the top with a strip of filter paper in order to close and complete the pod.
A serious drawback to the feeding-dosing unit described above is that the powdered coffee is not distributed uniformly inside the circular pod impressions.
The principal cause of this drawback is the fact that the coffee, pushed by the piston element in the feed tube, drops down into the impressions in an uncontrolled and uneven manner and not even the action of the pressers is able to distribute the coffee uniformly in the impressions.
The result using the type of feeder-doser described above is a coffee pod which does not meet quality specifications.
This considerable drawback worsens as the operating speed of the pod maker-filler machine increases.
The aim of the present invention is to produce a feeder unit which overcomes the drawbacks cited above.
In particular, the aim of the present invention is to produce a coffee feeder unit for a packing machine that produces filter paper coffee pods of the specified quality and which operates at high production speeds.